subcutaneous

adj. situated under the skin; administered under the skin (as of an injection)

The subcutis is the layer of tissue directly underlying the cutis. It is mainly composed of adipose tissue. Its physiological function includes insulation and storage of nutrients.Subcutaneous injections are given by injecting a fluid or a solid pellet into the subcutis. It is used to administer a variety of medical treatments. Subcutaneous injections of fluid are used to administer vaccines and medications. A pellet may be injected to deliver long-lasting doses of medication such as goserelin.
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Adjective
1. relating to or located below the epidermis; "hypodermic needle"; "subcutaneous implant"
(synonym) hypodermic
(pertainym) skin, tegument, cutis

(a.)
Situated under the skin; hypodermic.
  

Beneath the skin.